These studies will examine changes in the metabolism of monoamines (dopamine, norepinephrine, and serotonin) in brains and peripheral organs of alcohol-treated animals. The study of monoamine metabolism has been specifically chosen because there is strong belief that these amines play a role in euphoria-depression and insomnia, which are among the prominent symptoms of alcoholism. Previous studies have also indicated that monoamine metabolism could be affected by alcohol intake. For the first time the effects of acute and chronic alcohol treatments and alcohol abstinence (of chronically treated animals) on monoamine metabolism will be compared. Also in contrast to most previous studies, which only examined urinary monoamine excretion, the tissue levels of endogenous monoamines, the turnover of H3-labelled monoamines and of their metabolites will be investigated. The synthesis rate of norepinephrine, dopamine, epinephrine (in the adrenal gland), and serotonin will be estimated in animals receiving the corresponding radioactive precursor amino acids (thyrosine and tryptophan). The rates of monoamine synthesis will be correlated with the activities of the rate-limiting enzymes involved in monoamine synthesis (tyrosine hydroxylase, phenylethanolamine-N-methyl transferase, tryptophan hydroyxlase). The direct effects of alcohol on norepinephrine synthesis will be examined in an in vitro system using brain slices. The effects of alcohol on the permeability of the blood-brain barrier to norepinephrine administered peripherally will also be considered.